China is feeling the heat. Instead of a smooth series of positive images ahead of the Beijing Games, the grand plans for a world tour by the Olympic torch have produced a new international sport: extinguishing the flame as a pro-Tibet protest.

At the weekend there were damaging scenes of a squad of Chinese attendants jostling demonstrators in London. After the disruption of the torch’s progress through Paris comes the sight of protesters on the Golden Gate bridge in San Francisco. These are not reasons to curtail the tour. On the contrary, the “journey of harmony” is a valuable chance to give Beijing vivid proof that significant swathes of international opinion deeply oppose the recent crackdown. The protests gain added power ahead of the torch’s trip through Tibet itself.